1. Field of the Invention
The present invention relates generally to a navigation device and method in which a route for a mobile object is determined using a navigation system, and in particular, to a navigation device and method in which a route from a mobile deviation position to a destination is determined using a multi-route when the mobile object deviates from the route.
2. Description of the Related Art
In general, navigation systems are installed in a variety of mobile objects such as a ship, an aircraft, a vehicle and the like. The navigation system informs a driver of current position, calculates an optimal route to a desired destination, and guides the driver on the route. To do so, the navigation system receives GPS (Global Positioning System) information including latitude, longitude and altitude from a plurality of satellites belonging to a GPS to calculate current mobile position. In the navigation system, map matching is performed using current position and previously stored map data, and driving position is tracked on a map to provide guidance from the current position to the destination. In this way, the optimal route from the current position to the desired destination can serve the driver. However, even though the mobile object is navigated, the mobile object may deviate from the route due to driver's carelessness or other causes.
When the mobile object deviates from the route, the navigation system ignores all routes previously searched, and re-searches (re-routes) a route from the deviated position to the destination. This is disadvantageous because it takes a long time to re-search a new route, and so the route to the destination cannot be promptly provided for a user. Further, when the route from the deviation position to the destination is re-searched, current vehicle direction and features (e.g. U-turn) of the currently traveled road are not considered. As a result, the driver may actually take a less-than-optimal route under guidance of the navigation system.